Managing External Resources’ Exposure Using IGWs and NAT Gateways

One of the key purposes of setting up a VPC is to host resources such as EC2 instances (e.g., web servers). These resources often require access to the internet to download software updates, patches, and more. Another key network requirement is to allow inbound connections from the internet, for example, to allow customers to access your web application. When doing this, you would set up firewall rules to define what type of traffic will be permitted to make inbound connections to your web servers from the internet.

Accessing external resources and/or allowing inbound connectivity from the internet requires configuring and deploying gateways such as an internet gateway. Once this is configured, your VPC is then internet enabled. However, you still need to define how traffic is routed from the resources in the subnets of your VPC to the gateway to facilitate external access. Similarly, inbound connections from...